| Common mathematical functions | |||||||||||||||||||||||||||||||
| Mathematical special functions(C++17) | |||||||||||||||||||||||||||||||
| Mathematical constants(C++20) | |||||||||||||||||||||||||||||||
| Basic linear algebra algorithms(C++26) | |||||||||||||||||||||||||||||||
| Data-parallel types (SIMD)(C++26) | |||||||||||||||||||||||||||||||
| Floating-point environment(C++11) | |||||||||||||||||||||||||||||||
| Complex numbers | |||||||||||||||||||||||||||||||
Numeric array (valarray) | |||||||||||||||||||||||||||||||
| Pseudo-random number generation | |||||||||||||||||||||||||||||||
| Bit manipulation(C++20) | |||||||||||||||||||||||||||||||
| Saturation arithmetic(C++26) | |||||||||||||||||||||||||||||||
| Factor operations | |||||||||||||||||||||||||||||||
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| Interpolations | |||||||||||||||||||||||||||||||
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| Generic numeric operations | |||||||||||||||||||||||||||||||
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| C-style checked integer arithmetic | |||||||||||||||||||||||||||||||
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| Nearest integer floating point operations | |||||||||||||||||||||||||||||||||||||||||
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| Floating point manipulation functions | |||||||||||||||||||||||||||||||||||||||||
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| Classification and comparison | |||||||||||||||||||||||||||||||||||||||||
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| Types | |||||||||||||||||||||||||||||||||||||||||
| Macro constants | |||||||||||||||||||||||||||||||||||||||||
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Defined in header <cmath> | ||
| (1) | ||
float exp(float num); double exp(double num); | (until C++23) | |
/*floating-point-type*/ exp(/*floating-point-type*/ num); | (since C++23) (constexpr since C++26) | |
float expf(float num); | (2) | (since C++11) (constexpr since C++26) |
longdouble expl(longdouble num); | (3) | (since C++11) (constexpr since C++26) |
SIMD overload(since C++26) | ||
Defined in header <simd> | ||
template</*math-floating-point*/ V> constexpr/*deduced-simd-t*/<V> | (S) | (since C++26) |
Additional overloads(since C++11) | ||
Defined in header <cmath> | ||
template<class Integer> double exp( Integer num); | (A) | (constexpr since C++26) |
std::exp for all cv-unqualified floating-point types as the type of the parameter.(since C++23)S) The SIMD overload performs an element-wise std::exp onv_num.
| (since C++26) |
A) Additional overloads are provided for all integer types, which are treated asdouble. | (since C++11) |
Contents |
| num | - | floating-point or integer value |
If no errors occur, the base-e exponential ofnum (enum
) is returned.
If a range error occurs due to overflow,+HUGE_VAL,+HUGE_VALF, or+HUGE_VALL is returned.
If a range error occurs due to underflow, the correct result (after rounding) is returned.
Errors are reported as specified inmath_errhandling.
If the implementation supports IEEE floating-point arithmetic (IEC 60559),
For IEEE-compatible typedouble, overflow is guaranteed if709.8 < num, and underflow is guaranteed ifnum < -708.4.
The additional overloads are not required to be provided exactly as(A). They only need to be sufficient to ensure that for their argumentnum of integer type,std::exp(num) has the same effect asstd::exp(static_cast<double>(num)).
#include <cerrno>#include <cfenv>#include <cmath>#include <cstring>#include <iomanip>#include <iostream>#include <numbers> // #pragma STDC FENV_ACCESS ON constevaldouble approx_e(){longdouble e{1.0};for(auto fac{1ull}, n{1llu}; n!=18;++n, fac*= n) e+=1.0/ fac;return e;} int main(){std::cout<<std::setprecision(16)<<"exp(1) = e¹ = "<< std::exp(1)<<'\n'<<"numbers::e = "<<std::numbers::e<<'\n'<<"approx_e = "<< approx_e()<<'\n'<<"FV of $100, continuously compounded at 3% for 1 year = "<<std::setprecision(6)<<100* std::exp(0.03)<<'\n'; // special valuesstd::cout<<"exp(-0) = "<< std::exp(-0.0)<<'\n'<<"exp(-Inf) = "<< std::exp(-INFINITY)<<'\n'; // error handlingerrno=0;std::feclearexcept(FE_ALL_EXCEPT); std::cout<<"exp(710) = "<< std::exp(710)<<'\n'; if(errno==ERANGE)std::cout<<" errno == ERANGE: "<<std::strerror(errno)<<'\n';if(std::fetestexcept(FE_OVERFLOW))std::cout<<" FE_OVERFLOW raised\n";}
Possible output:
exp(1) = e¹ = 2.718281828459045numbers::e = 2.718281828459045approx_e = 2.718281828459045FV of $100, continuously compounded at 3% for 1 year = 103.045exp(-0) = 1exp(-Inf) = 0exp(710) = inf errno == ERANGE: Numerical result out of range FE_OVERFLOW raised
(C++11)(C++11)(C++11) | returns2 raised to the given power (\({\small 2^x}\)2x) (function)[edit] |
(C++11)(C++11)(C++11) | returnse raised to the given power, minus1 (\({\small e^x-1}\)ex-1) (function)[edit] |
(C++11)(C++11) | computes natural (basee) logarithm (\({\small\ln{x}}\)ln(x)) (function)[edit] |
| complex basee exponential (function template)[edit] | |
| applies the functionstd::exp to each element of valarray (function template)[edit] | |
C documentation forexp | |
